A sequencing batch reactor system for high-level biological nitrogen and phosphorus removal from abattoir wastewater.
A sequencing batch reactor (SBR) system is demonstrated to biologically remove nitrogen, phosphorus and chemical oxygen demand (COD) to very low levels from abattoir wastewater. Each 6 h cycle contained three anoxic/anaerobic and aerobic sub-cycles with wastewater fed at the beginning of each anoxic/anaerobic period. The step-feed strategy was applied to avoid high-level build-up of nitrate or nitrite during nitrification, and therefore to facilitate the creation of anaerobic conditions required for biological phosphorus removal. A high degree removal of total phosphorus (>98%), total nitrogen (>97%) and total COD (>95%) was consistently and reliably achieved after a 3-month start-up period. The concentrations of total phosphate and inorganic nitrogen in the effluent were consistently lower than 0.2 mg P l(-1) and 8 mg N l(-1), respectively. Fluorescence in situ hybridization revealed that the sludge was enriched in Accumulibacter spp. (20-40%), a known polyphosphate accumulating organism, whereas the known glycogen accumulating organisms were almost absent. The SBR received two streams of abattoir wastewater, namely the effluent from a full-scale anaerobic pond (75%) and the effluent from a lab-scale high-rate pre-fermentor (25%), both receiving raw abattoir wastewater as feed. The pond effluent contained approximately 250 mg N l(-1) total nitrogen and 40 mg P l(-1) of total phosphorus, but relatively low levels of soluble COD (around 500 mg l(-1)). The high-rate lab-scale pre-fermentor, operated at 37 degrees C and with a sludge retention time of 1 day, proved to be a cheap and effective method for providing supplementary volatile fatty acids allowing for high-degree of biological nutrient removal from abattoir wastewater.
Lemaire
Romain
R
Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, 4072, Australia. lemaire_rom@yahoo.com.au
Yuan
Zhiguo
Z
Bernet
Nicolas
N
Marcos
Marcelino
M
Yilmaz
Gulsum
G
Keller
Jürg
J
D000003:Abattoirs; D000641:Ammonia / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D005285:Fermentation; D007220:Industrial Waste / Q000032:analysis*; D009584:Nitrogen / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods; D014867:Water / Q000737:chemistry
D007220:Industrial Waste; D014867:Water; D010758:Phosphorus; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen